ALDEN WILLIAMS/FAIRFAX NZ
Anna Youngman has to wear a mask on her property due to the risk of crystalline silica from the neighbouring quarry.

ACC is a shareholder in the company behind a quarry causing health concerns for Christchurch residents.

The quarry, run by Winstone Aggregates Ltd, has led to considerable health concerns in the Yaldhurst area. It was given permission in 2015 to expand onto rural-zoned land and is now within 90 metres of one house and 150m from others.

Residents on Old West Coast Rd have been wearing face masks on their own properties after health officials raised concerns about the risk of inhaling dust containing crystalline silica.

Considered to be a serious long-term health risk, crystalline silica can cause lung cancer and silicosis, an irreversible disease.

Two tests – one commissioned by residents, the other by Environment Canterbury – showed the dust contained 30 per cent silica. Some residents said the dust was "killing us".

The sole shareholder of Winstone Aggregates is Firth Industries Ltd, a subsidiary of Tenon Holdings Ltd, a New Zealand-domiciled, United States-focussed business, which is in turn a subsidiary of listed company Rubicon Limited.

Rubican Limited, a New Zealand-based holding company, has seven directors, including New Zealand businessmen Hugh Fletcher and Simon Moriarty, one Greek-based director and five US-based directors.

Formed in 2001 as part of the break-up of the Fletcher Challenge group, its shareholders include, among others, HSBC Nominees NZ Ltd, Citibank Nominees NZ Ltd, JP Morgan Chase Bank, ACC and Fletcher Brothers.

The corporation came under fire last year for its indirect investments in Lockheed Martin – a company ACC was not allowed to invest in because of its involvement in the development or production of cluster munitions.

It was also found to have indirect investments in British American Tobacco when Government policy prohibits investment in tobacco companies. It had also invested in companies with poor environmental and human rights records.

A spokesperson for ACC declined to comment when asked if it was aware that the dust from the Winstone Aggregates Ltd quarry was linked to health problems for Christchurch residents.

"ACC does not publicly comment on the operational matters of listed companies in which we have shareholdings," the spokesperson said.